For the Republican Party, Christine O'Donnell's win in the Delaware Senate primary symbolized an identity crisis within the GOP that could complicate its push for big gains in the fall elections that will decide control of Congress.

The "Tea Party" movement struck another blow against the Republican establishment Tuesday as a little-known conservative candidate beat veteran Rep. Mike Castle in Delaware's Senate primary, setting up a key battleground for the November general election.

Republican Sen. Lisa Murkowski trailed her lesser-known conservative opponent Wednesday in a surprisingly tight race, but with nearly all the election day ballots counted, the race was too close to call.